Method of manufacturing a tape tab having a rounded user&#39;s end

ABSTRACT

A method of manufacturing tape tabs for use in disposable absorbent articles such as diapers. The method includes steps of cutting a unitary strip of material along parallel curved transverse lines to product tab shapes in the strip material having rounded corners, doubling over the strip material into itself to form a gripping area, and cutting the strip material along parallel cut lines which extend from the curved transverse cut lines to the longitudinal edge to form individual tape tabs.

FIELD OF THE INVENTION

The invention relates to a method of manufacturing a tape tab for use inan absorbent article, the tape tab having a rounded user's end.

The invention also relates to a tape tab for a disposable absorbentarticle and to a disposable absorbent article comprising such a tapetab.

BACKGROUND OF THE INVENTION

From EP-A-0 379 850, a method is known for producing a tape system froma unitary strip, the tapes having rounded user's ends. According to themethod of the above patent application, a longitudinal unitary strip ofmaterial is coated with adhesive, such that a central adhesive-free zoneis present. A number of parallel, transversely extending straight cutlines are made, running from both longitudinal sides of the unitarystrip towards the longitudinal center line. Two sinusoidal, longitudinalcut lines, bridge the straight-line, transverse cuts on both sides ofthe longitudinal center line to form individual tape tabs which eachhave an adhesive-free, rounded user's end.

A disposable absorbent article having tapered tape tabs with roundeduser gripping parts is known from EP-A-0 233 704. The tapes are cut froma single strip of elongated material, in such a way that no scrap isproduced. This is achieved by cutting the strip along straighttransverse cut lines, running from the longitudinal sides of the striptowards the center line, the cut lines on opposite sides of thelongitudinal center line being displaced relative to one another by halfa tape width. A single, sinusoidal cut-line extends in the length of thestrip, along the longitudinal center line of the strip to form therounded user's end on each tape tab.

A disposable absorbent article having a tape tab comprising a combinedadhesive fastener and a tape fastener is known from EP-A-0 321 132. Inthis patent application a tape tab is shown having a doubled-over user'send and a fastening surface to which a patch of VELCRO material isattached. An additional adhesive patch on the fastening surface of thetape tab provides for a disposal means to maintain the diaper in arolled up or folded disposal-configuration after use. Because the endparts of the tapes are doubled over, the end parts are rounded along thethickness of the tape, and provide user-friendly gripping parts.

It is an object of the invention to provide a tape tab having at itsuser's end a gripping part that allows easy handling by the user, andwhich comprises a reinforcement area.

It is again an object of the invention to provide a tape tab that isbaby-friendly and which minimizes the chances of skin-irritation uponwearing.

It is a further object of the present invention to provide a method ofproducing tape tabs from a unitary strip of material, in which the scrapproduced on cutting is minimized.

It is another object of the present invention, to provide a method ofmaking a tape tab for use in a disposable absorbent article, the tapetab having a rounded user-end.

SUMMARY OF THE INVENTION

The method according to the invention is characterized by:

a. cutting a unitary strip of material along parallel, spaced apartcurved transverse cut lines, wherein the unitary strip of materialcomprises two longitudinal edges, the transverse cut lines extendingfrom a first longitudinal edge in the direction of the secondlongitudinal edge, each curved cut line forming the contour of a roundedcorner of the user's end of a first tape tab and forming a sideextension of the user's end of a second tape tab which is adjacent thefirst tape tab,

b. doubling over of each side extension onto itself along a fold line toform the gripping parts, and

c. cutting the unitary strip of material along further parallel cutlines which extend from the curved transverse cut lines to the secondlongitudinal edge to form individual tape tabs.

By cutting the tapes along the curved cut lines, the material that iscut off the corner of one tape tab, remains attached to the neighboringtape tab to form a side extension of the neighboring tape tab. Byfolding back the side extension onto itself, a reinforced user's end isformed having a rounded corner. When the tape tabs are attached to anabsorbent article, the rounded corner is closest to the waist edge ofthe absorbent article. The rounded corner reduces the chance of injuryto the baby wearing the absorbent article, and can be easily gripped bythe mother at the lower, doubled-over corner. The tape tabs can beadhesive tape tabs, mechanical tape tabs, or combinations thereof.

Adhesive tape tabs are attached at their manufacturer's end to anabsorbent article, the user's end of the tape tabs, before use of theabsorbent article, being glued to a release surface. An adhesive tapetab according to the present invention can be easily detached from therelease surface, for application of the article to a baby, by liftingthe doubled over user's-end with a finger tip and pealing back the tape.The doubled-over user's end does not become attached to the backsheet ofthe absorbent article upon application of the article to a baby, andforms a reinforced gripping part which can easily be lifted. Hence thetape tab according to the invention also provides for easy detachment ofthe tapes on removal of the absorbent article from the baby after use orfor adjustment and reattachment of the tape tabs during use.

No scrap material is produced by the method of manufacturing tape tabsaccording to the invention.

In an embodiment or the method according to the invention, curvedtransverse cut lines are formed along a longitudinal edge of the unitarystrip, to form cut-out sections. By folding over of one cut-out section,rounded corners of each time two neighboring tape tabs are formed. Thetape tabs made according to this embodiment have two rounded corners attheir user's end.

In a further embodiment of the method according to the invention, onesurface of the unitary strip of material is provided with an adhesiveand is covered with a unitary release strip. The combined unitary stripof material and the release strip are cut along transverse cut lines toform individual, composite tape tabs. The composite tape tabs eachcomprise a fastening member and a release member. The length of the tapetabs corresponds to the width of the unitary strip of material fromwhich the tape tabs are cut. In one embodiment, the release strip is ofequal width as the unitary strip of material, such that for a compositetape tab the fastening member and the release member are equal inlength.

The attachment of the tape tabs to an absorbent article by themanufacturer can occur in several ways.

In case the tape tabs are comprised of a single fastening member onlyand do not comprise a release member, the manufacturer's end of the tapetabs can be directly attached to the backsheet of the absorbent article.Prior to attachment of these tape tabs, the absorbent article can havebeen provided with a reinforcement material in the anchoring regions inwhich the manufacturer's ends of the tape tabs are to be attached. Thediaper can in such a case also comprise a release surface which isattached to the topsheet and to which the user's end of the tape tabscan be applied on assembly of the diaper by the manufacturer.

The tape tabs can comprise near their user's end a pressure sensitiveadhesive or a mechanical fastening means of the type described in U.S.Pat. No. 5,180,534, U.S. Pat. No. 5,058,247 and U.S. Pat. No. 5,116,563,which fastening means easily detaches from the reinforcement materialthat is attached to the topsheet. At the manufacturer's end, the tapetabs can be provided with a strong adhesive which permanently attachesto the reinforcement material of the absorbent article.

In case the tape tabs are comprised of composite tape tabs, the releasemember of the tape tabs can be permanently fastened to the absorbentarticle by means of a relatively aggressive adhesive.

In this case, the reinforcement material in the anchoring regions on theabsorbent article, is formed by the release member and need not bepre-applied. In case the release member is shorter in length than thefastening member, the fastening member of the composite tape tabs is atthe manufacturer's end fastened directly to the backsheet of theabsorbent article. In a further embodiment of a method according to theinvention, the fold line of the side extensions of the tape tabscomprises a curved section located between two straight short fold lineson either side of the curved section. The curved section of the foldline is cut through, while the straight parts of the fold line arecreased or perforated. By folding-over the side extension of each tapetab along the straight parts of the fold line, the tapes are at theuser's end provided with two rounded corners instead of one roundedcorner and one angled corner.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in detail with reference to theaccompanying drawings. In the drawings:

FIG. 1 shows a partially cut-away plan view of an absorbent articlecomprising a pair of tape tabs according to the invention,

FIG. 2 shows a schematic side view of a method for manufacturing tapetabs according to the invention,

FIG. 3 shows a top view of a unitary strip of material used in themethod of FIG. 2,

FIG. 4 shows a plan view of a composite tape tab according to theinvention,

FIG. 5 shows a plan view of three neighboring tape tabs according to theinvention before the formation of individual tape tabs,

FIG. 6 shows a cross sectional view of the composite tape tab of FIG. 4along the line I—I,

FIG. 7 shows a cross-sectional view of the composite tape tab of FIG. 4wherein the manufacturer's end of the tape tab is attached to anabsorbent article,

FIG. 8 shows a plan view of three neighboring tape tabs and anindividual tape tab having two rounded corners at the user's end,

FIGS. 9 and 10 show a plan view of three neighboring tape tabs havingtwo rounded corners at the user's end and comprising 45°-fold lines.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “absorbent article” refers to devices whichabsorb and contain body exudates, and, more specifically, refers todevices which are placed against or in proximity to the body of thewearer to absorb and contain the various exudates discharged from thebody. The term “disposable” is used herein to describe absorbentarticles which are not intended to be laundered or otherwise restored orreused as an absorbent article (i.e., they are intended to be discardedafter a single use and, preferably, to be recycled, composted orotherwise disposed of in an environmentally compatible manner). A“unitary” absorbent article refers to absorbent articles which areformed of separate parts united together to form a coordinated entity sothat they do not require separate manipulative parts like a separateholder and liner. A preferred embodiment of an absorbent article of thepresent invention is the unitary disposable absorbent article, diaper 1,shown in FIG. 1. As used herein, the term “diaper” refers to anabsorbent article generally worn by infants and incontinent persons thatis worn about the lower torso of the wearer. It should be understood,however, that the present invention is also applicable to otherabsorbent articles such as incontinent briefs, incontinentundergarments, diaper holders and liners, and the like.

FIG. 1 is a plan view of the diaper 1 of the present invention in itsflat-out, state (i.e., with elastic induced contraction pulled out) withportions of the structure being cut-away to more clearly show theconstruction of the diaper 1 and with the portion of the diaper 1 whichfaces or contacts the wearer, the inner surface, oriented towards theviewer. As shown in FIG. 1, the diaper 1 preferably comprises aliquid-permeable topsheet 3; a liquid impervious backsheet 5 joined withthe topsheet; an absorbent core 7 positioned between the topsheet 3 andthe backsheet 5; side panels 9; elasticized stand-up leg cuffs not shownin FIG. 1 an elastic waist feature 13 and a fastening system 21, 23.

FIG. 1 shows a preferred embodiment of the diaper 1 in which thetopsheet 3 and the backsheet 5 have length and width dimensionsgenerally larger than those of the absorbent core 7. The topsheet 3 andthe backsheet 5 extend beyond the edges of the absorbent core 7 tothereby form the periphery 12 of the diaper 1. While the topsheet, thebacksheet, and the absorbent core may be assembled in a variety of wellknown configurations, preferred diaper configurations are describedgenerally in U.S. Pat. No. 3,860,003 entitled “Contractable SidePortions for Disposable Diaper” which issued to Kenneth B. Buell on Jan.14, 1975; and U.S. patent application Ser. No. 07/715,152 (abandoned),“Absorbent Article With Dynamic Elastic Waist Feature Having APredisposed Resilient Flexural Hinge”, Kenneth B. Buell et al. filedJun. 13, 1991; each of which is incorporated herein by reference.

The absorbent core 7 may be any absorbent means which is generallycompressible, conformable, non-irritating to the wearer's skin, andcapable of absorbing and retaining liquids such as urine and othercertain body exudates. The absorbent core 7 may be manufactured in awide variety of sizes and shapes (e.g., rectangular, hourglass,“T”-shaped, asymmetric, etc.) and from a wide variety ofliquid-absorbent materials commonly used in disposable diapers and otherabsorbent articles such as comminuted wood pulp which is generallyreferred to as airfelt. Examples of other suitable absorbent materialsinclude creped cellulose wadding; meltblown polymers including coform;chemically stiffened, modified or cross-linked cellulosic; tissueincluding tissue wraps and tissue laminates; absorbent foams; absorbentsponges; superabsorbent polymers; absorbent gelling materials; or anyequivalent material or combinations of materials. The configuration andconstruction of the absorbent core may also be varied (e.g., theabsorbent core may have varying caliper zones, a hydrophilic gradient, asuperabsorbent gradient, or lower average density and lower averagebasis weight acquisition zones; or may comprise one or more layers orstructures). The total absorbent capacity of the absorbent core 7should, however, be compatible with the design loading and the intendeduse of the diaper 1. Further, the size and absorbent capacity of theabsorbent core 7 may be varied to accommodate wearers ranging frominfants through adults. Exemplary absorbent structures for use as theabsorbent core 7 are described in U.S. Pat. No. 4,610,678 entitled“High-Density Absorbent Structures” issued to et al. on Sep. 9, 1986;U.S. Pat. No. 4,673,402 entitled “Absorbent Articles With Dual LayeredCores” issued to Weisman et al. on Jun. 16, 1987; U.S. Pat. No.4,888,231 entitled “Absorbent Core Having A Dusting Layer” issued toWeisman on Dec. 19, 1989; and U.S. Pat. No. 4,834,735, entitled “HighDensity Absorbent Members Having Lower Density and Lower Basis WeightAcquisition Zones”, issued to Alemany et al. on May 30, 1989. Each ofthese patents are incorporated herein by reference.

The backsheet 5 is positioned adjacent the garment surface of theabsorbent core 7 and is preferably joined thereto by attachment meanssuch as glue lines 14. The backsheet 5 may be secured to the absorbentcore 7 by a uniform continuous layer of adhesive, a patterned layer ofadhesive, or an array of separate lines, spirals, or spots of adhesive.Adhesives which have been found to be satisfactory are manufactured byH. B. Fuller Company of St. Paul, Minn. and marketed as HL-1258. Theattachment means will preferably comprise an open pattern network offilaments of adhesive as is disclosed in U.S. Pat. No. 4,573,986entitled “Disposable Waste Containment Garment”, which issued toMinetola et al. on Mar. 4, 1986 more preferably several lines ofadhesive filaments swirled into a spiral pattern such as is illustratedby the apparatus and methods shown in U.S. Pat. No. 3,911,173 issued toSprague, Jr. on Oct. 7, 1975; U.S. Pat. No. 4,785,996 issued to Ziecker,et al. on Nov. 22, 1978; and U.S. Pat. No. 4,842,666 issued to Wereniczon Jun. 27, 1989. Each of these Patents are incorporated herein byreference. Alternatively, the attachment means may comprise heat bonds,pressure bonds, ultrasonic bonds, dynamic mechanical bonds, or any othersuitable attachment means or combinations of these attachment means asare known in the art.

The backsheet 5 is impervious to liquids (e.g., urine) and is preferablymanufactured from a thin plastic film, although other flexible liquidimpervious materials may also be used. As used herein, the term“flexible” refers to materials which are compliant and will readilyconform to the general shape and contours of the human body. Thebacksheet 5 prevents the exudates absorbed and contained in theabsorbent core 7 from wetting articles which contact the diaper 1 suchas and undergarments. The backsheet 5 may thus comprise a woven ormaterial, polymeric films such as thermoplastic films of polyethene orpolypropylene or, or composite materials such as a film-coated nonwovenmaterial. Preferably, the backsheet is a film having a thickness of fromabout 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Particularlypreferred materials for the backsheet include RR821 blown films andRR5475 cast films as manufactured by Tredegar Industries, Inc. of TerreHaute, Ind. The backsheet 5 is preferably embossed and/or matte finishedto provide a more clothlike appearance. Further, the backsheet 5 maypermit vapors to escape from the absorbent core 7 (i.e. breathable,)while still preventing exudates from passing through the backsheet 5.

The topsheet 3 is positioned adjacent the body surface of the absorbentcore 7 and is preferably joined thereto and to the backsheet 5 byattachment means (not shown) such as those well known in the art.Suitable attachment means are described with respect to joining thebacksheet 5 to the absorbent core 7. As used herein, the term “joined”encompasses configurations whereby an element is directly secured to theother element by affixing the element directly to the other element, andconfigurations whereby the element is indirectly secured to the otherelement by affixing the element to intermediate member(s) which in turnare affixed to the other element. In a preferred embodiment of thepresent invention, the topsheet 3 and the backsheet 5 are joineddirectly to each other in the diaper periphery 12 and are indirectlyjoined together by directly joining them to the absorbent core 7 by theattachment means (not shown).

The topsheet 3 is compliant, soft feeling, and non-irritating to thewearer's skin. Further, the topsheet 3 is liquid pervious permittingliquids (e.g., urine) to readily penetrate through its thickness Asuitable topsheet may be manufactured from a wide range of materials,such as porous foams; reticulated foams; apertured plastic films; orwoven or nonwoven webs of natural (e.g., wood or cotton), synthetic(e.g., polyester or polypropylene or), or a combination of natural andsynthetic. Preferably, the topsheet 3 is made of a hydrophobic materialto isolate the wearer's skin from liquids contained in the absorbentcore 7. There are a number of manufacturing techniques which may be usedto manufacture the topsheet 3. For example, the topsheet 3 may be anonwoven web of, spunbonded, carded, wet-laid, meltblown,hydroentangled, combinations of the above, or the like. A preferredtopsheet is carded and thermally bonded by means well known to thoseskilled in the fabrics art. A preferred topsheet comprises a web ofstaple length polypropylene such as is manufactured by Veratec, Inc., aDivision of International Paper Company, of Walpole, Mass. under thedesignation P-8.

The diaper 1 preferably further comprises elasticized leg cuffs 11 forproviding improved containment of liquids and other body exudates. Eachelasticized leg cuff 11 may comprise several different embodiments forreducing the leakage of body exudates in the leg regions. (The leg cuffcan be and is sometimes also referred to as leg bands, side flaps,barrier cuffs, or elastic cuffs.) U.S. Pat. No. 3,860,003 describes adisposable diaper which provides a contractible leg opening having aside flap and one or more elastic members to provide an elasticized legcuff (gasketing cuff). U.S. Pat. No. 4,909,803 entitled “DisposableAbsorbent Article Having Elasticized Flaps” issued to Aziz et al. onMar. 20, 1990, describes a disposable diaper having “stand-up”elasticized flaps (barrier cuffs) to improve the containment of the legregions. U.S. Pat. No. 4,695,278 entitled “Absorbent Article Having DualCuffs” issued to Lawson on Sep. 22, 1987, describes a disposable diaperhaving dual cuffs including a gasketing cuff and a barrier cuff.

The Diaper 1 preferably further comprises an elastic waist feature 13that provides improved fit and containment. The elastic waist feature 13is that portion or zone of the diaper 1 which is intended to expand andcontract to dynamically fit the wearer's waist. The elastic waistfeature 13 at least extends longitudinally outwardly from at least oneof the waist edges of the absorbent core 7 and generally forms at leasta portion of the end edge of the diaper 1. Disposable diapers aregenerally constructed so as to have two elastic waist features, onepositioned in the first waist region 16 and one positioned in the secondwaist region 17, although diapers can be constructed with a singleelastic waist feature. Further, while the elastic waist feature or anyof its constituent elements can comprise a separate element affixed tothe diaper 1, the elastic waist feature 13 is preferably constructed asan extension of other elements of the diaper such as the backsheet 5 orthe topsheet 3, preferably both the backsheet 5 and the topsheet 3. Theelasticized waistband 13 may be constructed in a number of differentconfigurations including those described in U.S. Pat. No. 4,515,595issued to Kievit et al. on May 7, 1985 and the above referenced U.S.patent application Ser. No. 07/715,152 (abandoned); each of thesereferences being incorporated herein by reference.

In a preferred embodiment, the diaper also comprises elasticized sidepanels 15 disposed in the attachment areas of tabs 21, 23 and indicatedin FIG. 1 by the broken lines. The elasticized side panels 15 provide anelastically extensible feature that provides a more comfortable andcontouring fit by initially conformably fitting the diaper to the wearerand sustaining this fit throughout the time of wear well past when thediaper has been loaded with exudates since the elasticized side panelsallow the sides of the diaper to expand and contract. The elasticizedside panels 15 further provide more effective application of the diaper1 since even if the diaper pulls one elasticized side panel by pullingof tape tabs 21, 23 farther than the other during application(asymmetrically), the diaper 1 will “self adjust” during wear. While theelasticized side panels 15 may be constructed in a number ofconfigurations, examples of diapers with elasticized side panelspositioned in the ears (ear flaps) of the diaper are disclosed in U.S.Pat. No. 4,857,067, entitled “Disposable Diaper Having Shirred Ears”issued to Wood, et al. on Aug. 15, 1989; U.S. Pat. No. 4,381,781 issuedto Sciaraffa, et al. on May 3, 1983; U.S. Pat. No. 4,938,753 issued toVan Gompel, et al. on Jul. 3, 1990; and the hereinbefore referenced U.S.patent application Ser. No. 07/715,152 (abandoned); each of which areincorporated herein by reference.

The diaper 1 of FIG. 1 comprises in the waist region 16 two tape tabs21, 23. The tape tabs each comprise a manufacturer's end which isattached to the backsheet of the diaper 1 in an anchoring zone. Tape tab23 is shown in an extended position in which the adhesive fasteningsurface 27 of the user's end 32 of the tape tab 23 is facing upward. Themanufacturers end of the tape tabs 21, 23 is adhesively affixed to thebacksheet 5. As used herein, the user's end of the tape tabs 21, 23refers to the part that can be gripped by a user of the absorbentarticle and that can be attached to an attachment zone of backsheet toput the diaper 1 on a baby. The manufacturers end of the tape tabs 21,23 refers to the part that is permanently attached to an anchoring zoneof the topsheet 3 or to an anchoring zone of the backsheet 5.

A reinforcement element 31 attaches the tape tabs 21, 23 to the ananchoring zone of the topsheet 3. The reinforcement element 31 providesa strengthening of the topsheet 3 in the anchoring regions and preventsthe tapes from tearing off the topsheet 3 upon use. Preferably, thebacksheet 3 is also provided with a reinforcement material in theanchoring zone. The reinforcement element 31 extends beyond theperiphery 12 of the diaper and is attached to the adhesive fasteningsurface 27. Each tape tab 21, 23 comprises at its user's end 32 a sideextension 33, 34. The side extensions 33, 34 of the tape tabs aredoubled over onto the adhesive fastening surface 27 and are therebyprevented from unfolding. The doubled-over side extensions formreinforced gripping parts of the tape tabs 21, 23.

Upon application of the diaper to a baby, the user's ends of the tapetabs 21, 23 are attached to a landing zone of the backsheet that islocated in the second waist region 17, either directly onto thebacksheet 5 or onto a reinforced landing surface 18. The reinforcedlanding surface 18 can be formed by a single strip or by individualpatches of polyethylene or polypropylene and can be located on theoutward facing side of the backsheet 5 or can be located on the inwardfacing side thereof. The tape tabs can be released from the reinforcedlanding surface 18 without tearing of the backsheet and can be reappliedto the landing surface for re-adjustment of the diaper. The relationshipbetween the surface texture of the reinforced landing surface and theadhesive properties of the tape tabs, have been described in U.S. Pat.No. 3,867,940, U.S. Pat. No. 4,210,144, GB-A-2 129 689, EP-B-0 080 647and EP-B-0 286 030.

When the diaper 1 is placed on a baby, the doubled-over side extensions33, 34 at the user's ends of the tape tabs are located underneath theoutwardly facing surface of the tape tabs 21, 23. Hereby it is preventedthat the baby suffers any discomfort from contact with the sideextensions 33, 34. The positioning of the side extensions underneath theoutwardly facing surface of the user's ends of the tape tabs, also helpsin preventing the baby from loosening the tape tabs.

Before application of the diaper to the baby, the tape tabs 21, 23 aredoubled over such that the adhesive fastening surface 27 is located onthe reinforcement element 31, as is shown for tape tab 21 in FIG. 1. Theoutwardly-facing surface of the reinforcement element 31 is preferablysmooth such that the adhesive fastening surface 27 of the user's end 32easily detaches therefrom. The outer surface of the reinforcementelement 31 may be treated with a release coating, such as for instance asilicone coating. The doubled-over side extensions 33, 34 of tape tabs21, 23 allow the tapes to be easily lifted from the reinforcementelement 31 or from the reinforced landing surface 18.

FIGS. 2 and 3 respectively show a schematic side view of a productionline for manufacturing the tape tabs in accordance with the inventionand the unitary strip of material from which the individual tape tabsare formed in said production line. From a supply roll 51, a unitarystrip of material 52 is unwound in the direction of transport, which isindicated by the arrow T. The unitary strip of material 52 forms thefastening member for the tape tabs and is for instance formed of aplastic or paper backed material of a width of 6 cm and a thickness of130 micrometers, preferably coated with a pressure or heat sensitiveglue, such as supplied by 3M GmbH, Hansastr. 9, Neuss. The width of thestrip 52 corresponds to the length of the finished tape tabs.Alternatively, the strip of material 52 is coated with glue on line, asshown in FIG. 2. The unitary strip of material passes a diecutter 54,which comprises an upper knife roll assembly, and a lower cylindricalroll acting as an anvil roll which is contacted by the knife roll. Thediecutter 54 provides the strip 52 with a number of parallel, spacedapart, curved transverse cuts 56 as shown in FIG. 3, which extend fromthe longitudinal side 58 of the strip 52 in the direction of the secondlongitudinal side 60.

After passing through the die-cutter 54, the strip 52 passes through acreasing unit 61, in which the strip is provided with crease lines 62.The creasing unit comprises a lower roll 65 which is provided with a rimextending along the circumference of roll 65. The rim can be parallel tothe axis of roll 65, or it can be skewed around a section of the surfaceof roll 65. Roll 65 is adjusted against roll 67 such that the rim has aclearance of generally about half the thickness of the strip 52. The rimon the lower roll 65 presses the strip 52 against the cylindricalsurface of the upper roll 67, thereby forming crease- or fold lines 62in strip 52.

When glue is applied to the strip 52 on-line, a layer of pressuresensitive adhesive, such as available from Findley Euro B.V.,Rotkreuzweg 7, D-6380 Bad Homburg, is applied to the lower surface 49 ofstrip 52 via a glue nozzle 69. The layer of glue may comprise a spiralor other intermittent pattern, or can be applied as a continuous layer,for instance by means of slot coating. In the present embodiment, theadhesive is supplied to the nozzle from a storage tank 70. When apreglued strip 52 is used, the nozzle 69 and the storage tank 70 are notrequired.

In a folding unit 72, the side extensions 57 of the tape tabs aredoubled over onto the lower surface 49 of the strip 52. The sideextensions are formed by the areas of the strip 52 that are locatedbetween the fold lines 62 and the cut lines 56 near the longitudinalside 58 of the strip 52. The fastening surface of the strip 52 iscomprised of the lower surface 49 of the strip 52 in FIG. 2. The user'sends 101 of the tape tabs 88 which are formed from the strip 52, are inthis example located near the longitudinal side 58. The folding unit 72comprises a roll 73, which strains the surface of the strip 52 bypressing the strip out of the plane of transport, preferably such thatat roll 73, the strip 52 forms an obtuse angle. Thereby, the sideextensions 57 are pressed out of the plane of the strip 52 and standaway from the plane of the strip. The uplifted side extensions 57 arecaught behind a folding wire 75 which is located adjacent the lowersurface of the strip 52 and which extends generally perpendicular to theplane of the drawing. Upon transporting the strip 52 past the foldingwire 75, the side extensions 57 are folded onto the lower surface of thestrip 52, and are held in position by the double layer of adhesivelocated between the lower surface of the strip 52 and the doubled overside extensions 57.

By folding over of the side extensions 57, the rounded corners 77 andthe straight corners 79 of the tape tabs are formed. The strip 52 isafter formation of the rounded corners 77 combined with a release strip81, which is unwound from a supply roll 80. The release strip 81 can beof equal width as the user's end 101 of the strip 52, as is shown inFIGS. 6 and 7. The release strip can also be equal in width to the totalwidth of the user's end 101 and the manufacturer's end 103 of the strip52. In the nip 82, the release strip 81 is combined with the adhesivesurface of the strip 52. At the final stage of the tape forming process,the strip 52 is cut in a cutting unit 85 along transverse cut lines 83extending form the upper side 58 to the lower side 60 of both the strip52 and the release strip 81, to form the individual composite tape tabs88. The individual composite tape tabs comprise a fastening member and arelease member. The fastening member is formed by the cut off parts ofunitary strip of material 52. The release member is formed by the cutoff parts of the release strip 81. The length of the tape tabscorresponds to the width of the strip 52.

The transverse cut lines 83 should ideally be located at a fixedposition relative to the fold lines 62 of adjacent tape tab. Inpractice, the position of the transverse cut lines can be allowed tovary by a fraction of the distance between the rounded corner 56 of onetape tab and the fold line 62 of the neighboring tape tabs for instanceby 1 or 2 mm. Displacement of the transverse cut lines 83, which are forinstance caused by variations in the speed of the strip 52, can lead tocutting open of the fold lines 62 in the cutting unit 85. To minimizethe variation in the position of the transverse cut lines 83, an opticaldetector 87, such as a photo diode or a Charge Coupled Device (CCD) isplaced over the strip 52, upstream of the cutting unit 85, to measurethe position of the rounded corners 56 or the position of straight-edgecorners 79. The optical detector 87 can distinguish the boundary betweenthe strip 52 and the release strip 81. The signal of the opticaldetector 87 is fed back to the servo drives 89 and 90, which drive thecreasing unit 61 and the die-cutter 54. By controlling the speed oftransport of the strip 52, the transverse cut lines 83 can be located ata position along the strip 52 which varies by not more than 1 to 2 mm.

FIG. 4 shows an embodiment of a composite tape tab 93 comprising anupper fastening member 104 and an underlying release member 106, whichin this figure is only visible at upper left- and right hand corners ofthe tape tab 93. The composite tape tab 93 is similar to the tape tabsas formed in process as shown in FIGS. 2 and 3. The tape tab of FIG. 4is the mirror image of the tape tabs which are formed according to theprocess of FIG. 2. In effect, for attachment to an absorbent article,two tape tabs are required which are mirror images with respect to oneanother. The tape tab 93 of FIG. 4 can be formed in the process as shownin FIGS. 2 and 3 by providing the transverse cuts 56 at the lowerlongitudinal side 60 of the strip 52.

Preferably the fastening member 104 of the composite tape tab 93, whichfastening member is facing the viewer, is transparent, orsemitransparent. The folded-over side extension 94 and the roundedcorner 100 of the tape tab 93 result in a symmetrical appearance of thetape tab 93, even though the fold line 97 is straight and extendsgenerally in the direction of the longitudinal sides 95, 96 of the tapetab 93. The symmetrical shape of the transparent or semi-transparenttape tab 93 is of advantage if the tape tab is fastened on a landingsurface 18 on the backsheet of a diaper which is provided with opticalfit guides. The optical fit guides, as are provided on diapers asmarketed by The Procter & Gamble Company under the tradename PAMPERS,are applied to the backsheet 5 or to the landing surface 18 for the userto symmetrically place the tape tabs onto the diaper and hence allowproper fastening of the diaper around the baby. For a good fit, it isnot only important that the tape tabs 21, 23 are fastened in the rightposition along the transverse length of the absorbent article 1 of FIG.1 (in the direction of the short sides), but also that an accurateposition of the tape tabs is obtained along the longitudinal sides ofthe absorbent article. The latter is facilitated by tape tabs 93 whichhave a symmetrical appearance relative to their centerline.

In FIG. 5, three neighboring tape tabs 105, 107 and 109 are shown priorto being cut from a unitary strip of material 121 (having longitudinalsides 118, 119) to form individual tape tabs. The curved transverse cutlines 120 form, after doubling over of side extensions 110, roundedcorners 108. The fold line 111 of the tape tab 107 extends at an angleof 45° relative to the longitudinal sides 98, 99 of the tape tab. Theside extension 110 is doubled back onto the adhesive surface of the tapetab 107 and forms at the user's end 101 a gripping part by which thetape 107 can be gripped by a user to be lifted from its release surfaceand to be attached to the reinforced landing surface as shown in FIG. 1under reference numeral 18. The fold line 111 can be formed by a creaser65, 67, as described in FIG. 2, or can alternatively be formed by anumber of perforations which extend through the surface of the fasteningmember of the tape tab 107. The direction of transport of the unitarystrip 52 from which the tape tabs 105, 107 and 109 are formed, isindicated in FIG. 5 under T.

FIG. 6 shows a cross-sectional view of the tape tab of FIG. 4 along theline I—I. As shown in FIG. 6, the release member 106, which is formedfrom release strip 81, is located at the back of the composite tape tab93 and is placed against the user's end 101 of the fastening member 104.The user's end 101 and the manufacturer's end 103 of the fasteningmember 104 of the tape tab 93 are formed from a single, homogeneousstrip of material, which is a transversely cut-off part of the unitarystrip of material 52 in FIGS. 2 and 3.

The release member 106 comprises a crease line 123 along which the lowerpart of the release member is doubled over. The lower surface 117 of therelease member 106 is coated with an adhesive for attachment to thetopsheet of an absorbent article. The lower surface 114 of the fasteningmember 104 is coated with for instance a pressure sensitive adhesive. Asthe adhesively coated, doubled-over lower part 122 of the release member106 contacts the adhesive surface 114 of the fastening member 104, thedoubled over part 122 of the release member 106 is permanently attachedto the fastening member 104.

The upper surface 112 of the release member 106 is for instancesilicone-coated to easily detach from the adhesive surface 114 of thefastening member 104. As no adhesive is present between the sideextension 94 and the release member 106, the fastening member 104 can beeasily separated from the release member 106 at the position of the sideextension 94.

FIG. 7 shows the tape tab 93 in accordance with the invention when it isattached to the topsheet 115 and backsheet 116 of a diaper, before useof the diaper. The manufacturer's end of the fastening member 104 isadhesively attached to the backsheet 116 with a relatively aggressiveadhesive, that has preferably been pre-applied to the surface 114 of thefastening member. The release member 106 is with its surface 117adhesively attached to the topsheet 115 of the diaper.

Upon application of the diaper on the wearer, the user's end 101 of theattachment member 104 is peeled from the release surface 112 in thedirection of the arrow P, by lifting it by its doubled over sideextension 94, which forms a reinforced gripping part. When the fasteningmember 104 of the composite tape tab 93 is detached from the releasesurface 112 of the release member 106 up to the position of the lowerpart 122, further detachment of the fastening member is prevented by thestronger adhesion between the fastening member 104 and the releasemember 106 at the doubled-over end 122. When, upon detachment of thefastening member 104 by the user, the crease line 123 is reached, thedoubled-over part 122 unfolds by hinging backwards along the crease line123 such that tearing off of the user's end 101 of the fastening member104 by excessive pull force is prevented.

FIG. 8 shows a further embodiment of a method of manufacturing tape tabshaving rounded corners 136 at a user's end 130, in accordance with theinvention. A unitary strip of material 129 having longitudinal edges 133and 134, is transported in the direction indicated by arrow T. The strip129 is cut along curved transverse cut lines 135, which are regularlyspaced apart along the longitudinal edge 133 of the strip 129. Eachtime, two curved cut lines 135 define cut-out sections 137 which arelocated at the user's end 130 of the tape tabs. The user's end 130 andthe manufacturer's end 131 of the tape tabs are separated by a fold line141.

The cut-out sections 137 are doubled over onto the strip 129. In FIG. 8,the cut-out sections 137 have, before being folded over onto the strip129, been indicated by dotted lines. The cut-out sections 137 remainattached to the unitary strip of material 129. When the cut lines 135are formed, the strip 129 is also provided with crease or fold lines138. The fold lines 138 are in this embodiment generally parallel to thelongitudinal edges of the strip 129.

After cutting the transverse cut lines 135, the cut-out sections 137 arefolded toward the center of the strip 129 along fold lines 138. Afterfolding over of the cut-out sections 137, the individual tape tabs 150are formed by cutting the unitary strip 129 along parallel cut lines139, which run from the lower edge 134 of the strip 129 to the foldlines 138 and which cut through the doubled-over cut-out sections 137.

The user's end 130 of the tape tabs comprises an adhesive free area 140,by which the tape tabs can be lifted from the release member by theuser. Although no reinforced gripping part is formed by doubled overcut-out sections 137, the advantage of this embodiments is that tworounded corners are formed at the user's end and that no scrap isproduced.

FIG. 9 shows an embodiment of a method of manufacturing tape tabs 150having two rounded corners 136 at a user's end 130, in which the cut-outsections 137 along the longitudinal edge 133 of the tape tabs aredefined by two curved cut lines and one vertical cut line. The foldlines 138, along which the cut-out sections 137 are doubled over, areplaced at a 45° angle with respect to the transverse cut lines 139.Cutout sections 142, 143 are folded along fold lines 138 in thedirection of arrows F, to positions 142′ and 143′ respectively. Asymmetrical tape tab is obtained by this method having a fully roundeduser's end and having a reinforced gripping part.

For easy detachment of the fastening member of the tape tabs from therelease member, the areas 140 can be free of adhesive, or the adhesiveof areas 140 can be de-activated for instance by the application oftalcum powder.

FIG. 10 shows another embodiment of the method according to theinvention in which the cut-out sections 137, 144 are folded along 45°fold lines 138, the cut-out section being defined by two curved cutlines. The cut-out sections 137, 144 are folded back onto a single tapetab and is not cut by the transverse cut lines 139. A reinforcedgripping part is formed by the doubled-over cut out sections 137, 144 atthe user's end 130 of the tape tabs 150.

Preferably, the part of the cut-out sections 137, 144 that is located atthe top of the tape tabs, remains attached to the tape tabs. Thereto,the cut lines 135 do not continue all the way up to the center line ofeach tape tab.

What is claimed is:
 1. A method of manufacturing a tape tab for use in adisposable absorbent article, the tape tab having a generallylongitudinal shape and comprising a user's end which has a doubled-overgripping part, wherein the method comprises the steps of: a. cutting aunitary strip of material along parallel, spaced apart curved transversecut lines, wherein the unitary strip of material comprises twolongitudinal edges, the curved transverse cut lines extending from thefirst longitudinal edge in the direction of the second longitudinaledge, each said curved transverse cut line forming the contour of around corner of the user's end of a first tape tab and forming a sideextension of the user's end of a second tape tab which is adjacent thefirst tape tab, b. doubling over of each said side extension onto itselfalong a fold line to form the gripping part, the fold line and therounded corner forming an indented edge, the indented edge lyinglaterally inboard of the first longitudinal edge; and c. cutting theunitary strip of material along a second transverse cut line whichextends from the indented edge to the second longitudinal edge to formthe tape tab.
 2. A method of manufacturing a tape tab for use in adisposable absorbent article, the tape tab having a generallylongitudinal shape and comprising a rounded user's end, wherein themethod comprises the steps of: a. cutting a unitary strip of materialalong curved transverse cut lines, wherein the unitary strip of materialcomprises two longitudinal edges, the curved transverse cut linesextending from the first longitudinal edge in the direction of thesecond longitudinal edge, each said curved transverse cut line formingthe contour of a rounded corner of the user's end, wherein the curvedtransverse cut lines form a number of regularly spaced-apart partiallycut-out sections; b. doubling over of each said partially cut-outsection onto the unitary strip of material along a fold line, the foldline and the rounded corner forming an indented edge, the indented edgelying laterally inboard of the first longitudinal edge; and c. cuttingthe unitary strip of material along a second transverse cut line whichextends from the indented edge to the second longitudinal edge to formthe tape tab.
 3. A method according to claim 2 wherein the doubled-overpartially cut-out section forms a reinforced gripping part at the user'send of the tape tab.
 4. A method according to claim 1 wherein onesurface of the unitary strip of material is provided with an adhesive,which said surface after forming of the curved transverse cut lines, iscovered with a unitary release strip, the unitary strip of material andthe release strip forming, after the step of cutting along the secondtransverse cut line, a composite tape tab comprising a fastening memberand a release member.
 5. The method according to claim 4 wherein thewidth of the release strip is substantially equal to the width of thestrip of unitary material.
 6. The method according to claim 4 whereinthe release strip comprises a longitudinally extending release surfacefor releasable attachment to the tape tab and, adjacent to the releasesurface, a longitudinally extending fastening surface for permanentattachment to the tape tab.
 7. The method according to claim 4 whereinthe fold-lines comprise a curved cut-through section and a straight-linefold section to form a second rounded corner at the user's end of thetape tab.
 8. The method according to claim 1 wherein the fold lines areformed by a crease line or a line of perforations.
 9. The methodaccording to claim 1 wherein one surface of the unitary strip ofmaterial is coated with adhesive prior to doubling over of the sideextensions, the doubled-over side extensions being attached to thecoated surface.
 10. A tape tab for use in an absorbent article, the tapetab having a generally longitudinal shape and comprising a fasteningmember which at a user's end forms a doubled-over gripping part, thefastening member comprising in its flattened state, two longitudinalsides which extend in a generally parallel direction, the firstlongitudinal side forming a rounded corner at the user's end and thesecond longitudinal side forming a side extension, the side extensionbeing doubled-over to form the gripping part.
 11. A tape tab for use inan absorbent article, the tape tab having a generally longitudinal shapeand comprising a fastening member having two longitudinal sides, thefastening member comprising a user's end having two rounded corners, thefastening member comprising along at least one longitudinal side, nearthe user's end, a doubled-over side extension which side extension, inthe flattened state, is disposed on the user's end of the tape tab. 12.An absorbent article comprising a tape tab according to claim
 11. 13. Anabsorbent article comprising a tape tab according to claim
 10. 14. Amethod of manufacturing a tape tab for use in a disposable absorbentarticle, the tape tabs having a generally longitudinal shape andcomprising a rounded user's end, wherein the method comprises the stepsof: a. cutting a unitary strip of material along two curved transversecut lines and a first substantially straight transverse cut line,wherein: the unitary strip of material comprises first and secondlongitudinal edges, the curved transverse cut lines and thesubstantially straight transverse cut line extend from the firstlongitudinal edge in the direction of the second longitudinal edge, eachsaid curved transverse cut line forming a contour of a rounded corner ofthe user's end, and the curved transverse cut lines and thesubstantially straight transverse cut line cooperating to form a pair oflongitudinally opposed regularly spaced-apart partially cut-outsections, b. doubling over one of said partially cut-out sections ontothe unitary strip of material along a first fold line and the other oneof said partially cut-out sections along a second fold line, the foldlines and the rounded corners forming an indented edge, and c. cuttingthe unitary strip of material along a second transverse cut line whichextends from the indented edge to the second longitudinal edge to formthe tape tab.
 15. An absorbent article comprising a tape tab accordingto claim 14.